minor fixes of arxiv

Closes #1050

searx/engines/arxiv.py

 
 """
  ArXiV (Scientific preprints)
- @website     https://axiv.org
+ @website     https://arxiv.org
  @provide-api yes (export.arxiv.org/api/query)
  @using-api   yes
  @results     XML-RSS
 def response(resp):
     results = []
 
-    search_results = html.fromstring(resp.text).xpath('//entry')
+    dom = html.fromstring(resp.content)
+    search_results = dom.xpath('//entry')
 
     for entry in search_results:
         title = entry.xpath('.//title')[0].text
         url = entry.xpath('.//id')[0].text
 
         content_string = '{doi_content}{abstract_content}'
-       
+
         abstract = entry.xpath('.//summary')[0].text
 
         #  If a doi is available, add it to the snipppet
         try:
             doi_content = entry.xpath('.//link[@title="doi"]')[0].text
-            content = content_string.format(doi_content=doi_content, abstract_content=abstract_content)
+            content = content_string.format(doi_content=doi_content, abstract_content=abstract)
         except:
-            content = content_string.format(abstract_content=abstract_content)
+            content = content_string.format(doi_content="", abstract_content=abstract)
 
         if len(content) > 300:
                     content = content[0:300] + "..."

tests/unit/engines/test_arxiv.py

         self.assertRaises(AttributeError, arxiv.response, '')
         self.assertRaises(AttributeError, arxiv.response, '[]')
 
-        response = mock.Mock(text='''<?xml version="1.0" encoding="UTF-8"?>
+        response = mock.Mock(content=b'''<?xml version="1.0" encoding="UTF-8"?>
 <feed xmlns="http://www.w3.org/2005/Atom"></feed>''')
         self.assertEqual(arxiv.response(response), [])
 
-        xml_mock = '''<?xml version="1.0" encoding="UTF-8"?>
+        xml_mock = b'''<?xml version="1.0" encoding="UTF-8"?>
 <feed xmlns="http://www.w3.org/2005/Atom">
   <title type="html">ArXiv Query: search_query=all:test_query&amp;id_list=&amp;start=0&amp;max_results=1</title>
   <id>http://arxiv.org/api/1</id>
 </feed>
 '''
 
-        response = mock.Mock(text=xml_mock.encode('utf-8'))
+        response = mock.Mock(content=xml_mock)
         results = arxiv.response(response)
         self.assertEqual(type(results), list)
         self.assertEqual(len(results), 1)